This research proposal is concerned with aspects of influenza virus replication and structure. Analysis of virus membrane (M) protein will allow us to establish areas of hydrophobicity of the protein as possible sites for insertion into or interaction with the lipid bilayer. Studies are being carried out to understand the basis for the biochemical defects of temperature-sensitive mutants of influenza virus which fail to synthesize M and NS proteins in infected cells. The mutants are being analyzed for structural as well as regulatory defects.